Cutter head for longwall shearer

ABSTRACT

A cutter head for a longwall shearer includes a drum, a vane, and a plurality of cutting bits. The drum includes a first end and a second end and defines an axis of rotation extending therebetween. The vane is connected to the drum and extends in a helical manner along at least a portion of the axis. The vane defines an edge surface extending along an outer perimeter of the vane. The cutting bits are secured to the vane edge surface. Each cutting bit includes a block and a bit coupled to the block. The block is secured to the edge surface and extends beyond the outer perimeter of the vane.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of prior-filed, co-pending U.S.Provisional Application Ser. No. 61/799,366, filed Mar. 15, 2013, theentire contents of which are incorporate by reference herein.

BACKGROUND

The present invention relates to the field of mining machines.Specifically, the present invention relates to a cutter head for alongwall shearer.

A conventional shearer drum includes radial cutting bits positionedwithin bit holders. The drum includes a spiral vane having a loadingfence extending along the outer perimeter of the vane. The fence urgescut material into the space between the vane surfaces, and the vanecarries cut material from the mine face to a face conveyor behind theshearer drum. The vane includes notches formed along the loading fence,and bit holders are coupled to the vane in the notches. The bit holdershave a rectangular hole aligned along a radius extending from thelongitudinal axis of the drum. An outer edge of the loading fence has aconstant radius relative to the longitudinal axis of the drum, and theloading fence is a constant distance below the radius of the bit tips toprevent the loading fence from rubbing against solid, uncut material toprevent damage and ignition of flammable gas. In one embodiment, theminimum distance between the loading fence and the bit tips is about 100mm. U.S. Pat. No. 4,657,308 shows an example of a forward attack bit anda bit holder, which also requires a notched vane in the drum.

SUMMARY

In one aspect, the invention provides a longwall shearer for removingmaterial from a mine face. The longwall shearer includes a movablechassis, a first arm, a second arm, a first cutter head, and a secondcutter head. The first arm includes a first end pivotably coupled to thechassis and a second end. The second arm includes a first end pivotablycoupled to the chassis and a second end. The first cutter head includesa first drum, a first vane, and a plurality of first cutting bitscoupled to the first vane. The first drum is coupled to the second endof the first arm and defines a first axis of rotation. The first vaneextends in a helical manner along at least a portion of the first axisand defines a first edge surface. The first cutting bits are secured tothe first edge surface of the first vane and extend beyond the firstedge surface. The second cutter head includes a second drum, a secondvane, and a plurality of second cutting bits coupled to the second vane.The second drum is coupled to the second end of the second arm anddefines a second axis of rotation. The second vane extends in a helicalmanner along at least a portion of the second axis and defines a secondedge surface. The second cutting bits are secured to the second edgesurface of the second vane and extend beyond the second edge surface.

In another aspect, the invention provides a cutter head for a longwallshearer. The cutting head includes a drum, a vane, and a plurality ofcutting bits. The drum includes a first end and a second end and definesan axis of rotation extending therebetween. The vane is connected to thedrum and extends in a helical manner along at least a portion of theaxis. The vane defines an edge surface extending along an outerperimeter of the vane. The cutting bits are secured to the vane edgesurface. Each cutting bit includes a block and a bit coupled to theblock. The block is secured to the edge surface and extends beyond theouter perimeter of the vane.

In yet another aspect, the invention provides cutter head for a longwallshearer, the cutter head including a drum, a vane connected to the drum,a plurality of cutting bits, and a loading fence. The drum includes afirst end and a second end and defines an axis of rotation extendingtherebetween. The vane is connected to the drum and extends in a helicalmanner along at least a portion of the axis. The vane defines an edgesurface extending along an outer perimeter of the vane. The plurality ofcutting bits is secured to the vane edge surface. Each cutting bitincludes a block and a bit removably coupled to the block. The block issecured to the edge surface and extends beyond the outer perimeter ofthe vane. The block includes a slot, and the bit includes a tip and ashank received within the block slot. The shank defines a shank axisextending at an angle with respect to a line extending radially from thedrum axis. The loading fence is secured to the edge surface andprotrudes from the edge surface. The loading fence extends between twoadjacent cutting bit blocks in a direction generally parallel to thevane. The loading fence and sides of the cutting bit blocks form acontinuous loading surface.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a mining machine.

FIG. 2 is a side view of a cutter head.

FIG. 3 is a perspective view of a cutting bit assembly.

FIG. 4 is a reverse perspective view of the cutting bit assembly of FIG.3.

FIG. 5 is a top view of the cutting bit assembly of FIG. 3.

FIG. 6 is a side view of the cutting bit assembly of FIG. 3.

FIG. 7 is an exploded perspective view of a holder block and bit.

FIG. 8 is a perspective view of the cutter head of FIG. 2 with severalcutting bit assemblies removed.

FIG. 9 is a perspective view of a cutter head including a cutting bitassembly according to another embodiment.

FIG. 10 is a perspective view of the cutting bit assembly of FIG. 9.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. Use of “including”and “comprising” and variations thereof as used herein is meant toencompass the items listed thereafter and equivalents thereof as well asadditional items. Use of “consisting of” and variations thereof as usedherein is meant to encompass only the items listed thereafter andequivalents thereof. Unless specified or limited otherwise, the terms“mounted,” “connected,” “supported,” and “coupled” and variationsthereof are used broadly and encompass both direct and indirectmountings, connections, supports, and couplings.

FIG. 1 illustrates a longwall shearer 10 including a chassis or base 14and a pair of cutting assemblies 18. The base 14 is configured to tramalong a face (not shown) of material to be mined in a first direction 26and a second direction 28 opposite the first direction 26. As the base14 moves in the first direction 26, a first cutting assembly 18 a is ina leading position and a second cutting assembly 18 b is in a trailingposition. In the illustrated embodiment, the first cutting assembly 18 ais elevated to cut material, such as coal, from an upper portion of themine face, while the second cutting assembly 18 b is in a lower positionto cut material from a lower portion of the mine face.

Each cutting assembly 18 includes a ranging arm 30 and a cutter head 34.In the illustrated embodiment, the cutting assembly 18 also includes aguide assembly 38; in other embodiments, the cutting assembly 18 may notinclude the guide assembly 38. The ranging arm 30 is pivotably coupledto the base 14 on one end and rotatably supports the cutter head 34 onanother end.

As shown in FIG. 2, each cutter head 34 includes a drum 54, vanes 58,and a plurality of cutting bit assemblies or cutting bit systems 62coupled to the vanes 58. In the illustrated embodiment, the drum 54 hasa generally cylindrical shape. The drum 54 has a first end 70 and asecond end 74, and a drum axis 78 is defined therebetween. The first end70 is pivotably coupled to the ranging arm 30, and the second end 74engages the mine face. The drum 54 rotates about the drum axis 78 in afirst direction 82.

The vanes 58 are connected to the drum 54 and extend in a spiral orhelical manner along the periphery or outer surface of the drum 54,along at least a portion of the drum axis 78 between the first end 70and the second end 74. In the illustrated embodiment, the cutter head 34includes multiple vanes 58; in other embodiments, the cutter head 34 mayinclude one vane 58, or it may include fewer or more vanes 58 than theillustrated embodiment. The vane 58 defines an edge surface 84 proximatean outer perimeter of the vane 58 and a loading surface 86 extendingbetween the outer surface of the drum 54 and the edge surface 84. Theedge surface 84 includes a first or leading edge proximate the first end70 of the drum 54 and a second or trailing edge proximate the second end74 of the drum 54. The loading surface 86 is shaped or contoured tomatch the helical shape of the vane 58. As the drum 34 rotates, the vane58 urges the cut material from the second end 74 toward the first end70, where the cut material is deposited onto a face conveyor (not shown)below the chassis 10 (FIG. 1).

As shown in FIGS. 3 and 4, each cutting bit system 62 includes a holderblock 90, and bit 94, and a fence or loading plate 98. The holder 90includes side surfaces 102 proximate the edges of the edge surface 84,and a slot 110 extending through the holder block 90 (FIG. 4). Theholder block 90 is secured (for example, by welding) to the edge surface84 of the vane 58 and extends outwardly from the edge surface 84 in adirection that is generally perpendicular to the drum axis 78 (FIG. 2).The loading plate 98 is positioned between adjacent bit holder blocks 90to urge cut material into the space between the loading surfaces 86 ofthe vanes 58 and facilitate movement of the cut material away from themine face. The holder blocks 90 and plates 98 are coupled to one anotherand to the vane 58 (e.g., by welding). The holder blocks 90 and plates98 effectively form an integral loading surface that is continuous withthe loading surface 86 of the vane 58 to engage and scroll the cutmaterial toward the first end 70 of the drum 54.

Each holder block 90 includes at least one angled side surface 102 thatapproximately matches the contour of the adjacent loading surface 86.The side surface 102 is substantially flush with the loading surface 86,permitting the holder block 90 and the bit 94 to be aligned with theleading edge of the edge surface 84, or the edge proximate the first end70 of the drum 54. In the illustrated embodiment, the top surface ofeach holder block 90 is continuous with a respective loading fence 98immediately behind the block 90. Additionally, as best shown in FIGS. 5and 6, the side surface 102 of the holder block 90 is angled from top tobottom so that a top portion is aligned with the leading edge of thevane 58 and extends along the contour of the loading surface 86. Inaddition, the bit 94 is positioned so that a cutting tip 106 extendsbeyond the leading edge and is positioned over the space between theloading surfaces 86 of the vane 58. Since the side of the bit holderblock 90 and the bit 94 are positioned flush or nearly flush with theloading surface 86 of the vane 58, material that is cut by the bit 94 ismore likely to fall directly into the space between the loading surfaces86 of the vane 58 and scroll toward the first end 70. This configurationincreases the drum's loading efficiency, or the ability to carry cutmaterial from the mine face to the face conveyor.

In the illustrated embodiment, grooves are formed in the ends of theblocks 90 to facilitate positioning and attaching the loading plates 98to the holder blocks 90 by welding. As shown in FIGS. 3 and 4, theheight of the loading plate 98 varies along the length of the plate 98in order to facilitate loading of the cut material along the vane 58 andonto the face conveyor. The plate 98 is higher at its leading end whereit closely follows a bit 94 and holder block 90, and the height is lowerat the trailing end to prevent rubbing coal or rock. Thus, the higherleading end of the plate 98 moves through the rock more easily to engagemore of the cut material and carry the material toward the space betweenthe loading surfaces 86 of the vane 58.

As shown in FIG. 7, the bit 94 includes a first portion 122 having thetip 106 for engaging the mine face, a second portion or shank 126, and aretention hole 130. In the illustrated embodiment the holder block 90also includes an opening 114 and a spray nozzle 118 received within theopening 114 to spray fluid onto the cut material and/or the bit 94. Inthe illustrated embodiment, the bit 94 also includes a shoulder 134abutting the holder block 90. Also, in the illustrated embodiment, theshoulder 134 includes an opening 138 that is aligned with the opening114 for the spray nozzle 118. The spray nozzle 118 is secured within theopening 114 by a threaded connection, and the holder 90 has internalwater passages (not shown) to supply water or other fluid to the spraynozzle 118 from passages (not shown) in the drum vane 58.

The shank 126 extends away from the first portion 122 of the bit 94 andis received within the slot 110. In the illustrated embodiment, theretention hole 130 is positioned proximate an end of the shank 126 thatprotrudes from the slot 110 of the holder block 90. The bit 94 issecured to the holder block 90 by passing a pin 140 or other memberthrough the retention hole 130 to prevent the shank 126 from sliding outof the slot 110. As best shown in FIG. 4, the holder blocks 90 standproud of the edge surface 84 (i.e., extend above the edge surface 84),and the rear of the slot 110 is accessible behind the loading plate 98to facilitate assembly and removal of the bit 94.

Although FIGS. 3-6 show two holder blocks 90 and one loading plate 98coupled to the vane edge surface 84, it is understood that additionalcutting bit systems 62 are positioned along the length of the vane 58proximate a leading edge. In addition, the grooves between the blocks 90and the plate 98 may be filled in (e.g., by welding) in order to form asmooth surface between the plates 98 and the side surfaces 102 of theblocks 90. In addition, each cutting assembly 18 a, 18 b includescutting bit systems 62 that are oriented based on the rotation of thecutter drum 34. For example, one of the cutter heads 34 includes cuttingbit systems 62 with a “left” or counter-clockwise orientation and theother cutter head 34 includes cutting bit systems 62 with a “right” orclockwise orientation.

Referring to FIG. 8, the shank 126 defines a shank axis 142 that isoriented at an angle to a line intersecting the drum axis 78, ratherthan being aligned along a radial line extending from the axis 78. Inthe illustrated embodiment, the shank axis 142 is aligned with a linethat is substantially tangent to the edge surface 84 of the vane 58. Inone embodiment, the shank axis 78 may be aligned with a line that issubstantially tangent to the outer surface of the drum 54. The tip 106is angled toward the direction of rotation of the drum 54; the shank 126extends away from the direction of rotation of the drum 54, and isoriented at an angle that is more tangential relative to the drum 54than conventional forward attack bits.

Positioning the cutting bit assembly 62 on the edge surface 84 of thevane 58 permits the holder blocks 90 and bits 94 to become continuouswith the loading surface 86 rather than being positioned in notches ofthe loading surface 86. The tip of each bit 94 is substantially alignedwith the loading surface 86. The cutting bit system 62 simplifies theamount of disassembly required to remove broken bits 94 or accumulateddirt. In addition, the same bits 94 can be used for either cuttingassembly 18 a, 18 b, since the direction of rotation of each cutter head34 does not require separate bit geometry. The cutting bit system 62 isless expensive to produce and provides superior loading performancecompared to conventional conical-bit or radial-bit drums. Furthermore,the cutting bit system 62 reduces the complexity of manufacturing andmaintenance of the cutting assembly 18 a by reducing the need to formnotches on the vane 58 to support the holder 90.

FIGS. 9 and 10 illustrate a cutting bit system 462 according to anotherembodiment. Each holder block 490 and loading plate 498 is positioned onthe edge surface 84 of the vane 58. Each bit 494 includes a shank 526(FIG. 10) defining a shank axis 542 and is positioned within a slot 510of the holder block 490. The shank axis 542 is aligned radially withrespect to the drum axis 78. Each shank axis 542 is aligned to intersectthe drum axis 78. Also, the same bits 494 can be used for the cutterhead 34 of either cutting assembly 18 a, 18 b since the direction ofrotation of each cutter head 34 does not require separate bit geometry.

Thus, the invention provides, among other things, a cutter head for alongwall shearer. Although the invention has been described in detailwith reference to certain preferred embodiments, variations andmodifications exist within the scope and spirit of one or moreindependent aspects of the invention as described.

What is claimed is:
 1. A longwall shearer for removing material from amine face, the longwall shearer comprising: a movable chassis; a firstarm including a first end pivotably coupled to the chassis and a secondend; a second arm including a first end pivotably coupled to the chassisand a second end; a first cutter head including a first drum, a firstvane, and a plurality of first cutting bits coupled to the first vane,the first drum coupled to the second end of the first arm and defining afirst axis of rotation, the first vane extending in a helical manneralong at least a portion of the first axis and defining a first edgesurface, the first cutting bits secured to the first edge surface of thefirst vane and extending beyond the first edge surface; a second cutterhead including a second drum, a second vane, and a plurality of secondcutting bits coupled to the second vane, the second drum coupled to thesecond end of the second arm and defining a second axis of rotation, thesecond vane extending in a helical manner along at least a portion ofthe second axis and defining a second edge surface, the second cuttingbits secured to the second edge surface of the second vane and extendingbeyond the second edge surface.
 2. The longwall shearer of claim 1,wherein the first cutting bits are spaced apart along the first edgesurface, and wherein the first cutter head includes a loading fencesecured to the first edge surface and extending between two adjacentcutting bits in a direction generally parallel to the vane.
 3. Thelongwall shearer of claim 1, wherein each first cutting bit includes ablock secured to the first edge surface and a bit removably coupled tothe block.
 4. The longwall shearer of claim 3, wherein the bit includesa shank and a tip, wherein the block includes a slot for receiving theshank.
 5. The longwall shearer of claim 4, wherein the shank defines ashank axis, the shank axis extending at an angle with respect to a lineextending radially from the first axis.
 6. The longwall shearer of claim5, wherein the shank axis is substantially aligned along a line that istangent to the first edge surface.
 7. The longwall shearer of claim 1,wherein the first vane defines a contoured loading surface extendingbetween the first drum and the first edge surface, wherein each firstcutting bit has a tip that is aligned with the loading surface.
 8. Acutter head for a longwall shearer, the cutter head comprising: a drumincluding a first end and a second end and defining an axis of rotationextending therebetween; a vane connected to the drum and extending in ahelical manner along at least a portion of the axis, the vane definingan edge surface extending along an outer perimeter of the vane; and aplurality of cutting bits secured to the vane edge surface, each cuttingbit including a block and a bit coupled to the block, the block securedto the edge surface and extending beyond the outer perimeter of thevane.
 9. The cutter head of claim 8, wherein the plurality of cuttingbits are spaced apart at intervals along the edge surface.
 10. Thecutter head of claim 9, further comprising a loading fence secured tothe edge surface and protruding from the edge surface, the loading fenceextending between two adjacent cutting bit blocks in a directiongenerally parallel to the vane, the loading fence and the cutting bitblocks forming a continuous loading surface.
 11. The cutter head ofclaim 10, wherein the vane defines a loading surface extending betweenthe drum and the edge surface, wherein the loading fence is aligned withthe loading surface.
 12. The cutter head of claim 8, wherein the bit isremovably coupled to the block.
 13. The cutter head of claim 12, whereineach cutting bit further includes a pin, the bit including a hole forreceiving the pin to removably couple the bit to the block.
 14. Thecutter head of claim 8, wherein the bit includes a shank and a tip,wherein the block includes a slot for receiving the shank.
 15. Thecutter head of claim 14, wherein the shank defines a shank axis, theshank axis extending at an angle with respect to a line extendingradially from the drum axis.
 16. The cutter head of claim 15, whereinthe shank axis is substantially aligned along a line that is tangent tothe edge surface.
 17. The cutter head of claim 8, wherein the vanedefines a loading surface extending between the drum and the edgesurface, wherein the block includes a side surface that is generallycontinuous with the loading surface, and the bit having a tip that isaligned with the loading surface.
 18. A cutter head for a longwallshearer, the cutter head comprising: a drum including a first end and asecond end and defining an axis of rotation extending therebetween; avane connected to the drum and extending in a helical manner along atleast a portion of the axis, the vane defining an edge surface extendingalong an outer perimeter of the vane; a plurality of cutting bitssecured to the vane edge surface, each cutting bit including a block anda bit removably coupled to the block, the block secured to the edgesurface and extending beyond the outer perimeter of the vane, the blockincluding a slot, the bit including a tip and a shank received withinthe block slot, the shank defining a shank axis extending at an anglewith respect to a line extending radially from the drum axis; and aloading fence secured to the edge surface and protruding from the edgesurface, the loading fence extending between two adjacent cutting bitblocks in a direction generally parallel to the vane, the loading fenceand sides of the cutting bit blocks forming a continuous loadingsurface.
 19. The cutter head of claim 18, wherein the shank axis issubstantially aligned along a line that is tangent to the edge surface.20. The cutter head of claim 18, wherein the vane defines a loadingsurface extending between the drum and the edge surface, wherein theloading fence is aligned with the loading surface.
 21. The cutter headof claim 18, wherein the vane defines a loading surface extendingbetween the drum and the edge surface, wherein the block includes a sidesurface that is generally continuous with the loading surface, and thebit having a tip that is aligned with the loading surface.